angxiong Li

Purification of Produced Water by Ceramic Membranes: Material Screening, Process Design and Economics

Abstract Produced water, generated from underlying formations during the recovery of hydrocarbons, constitutes the largest waste stream associated with oil and gas production. Currently, over 90% of produced water is reinjected into the formation, either in support of enhanced oil recovery or for disposal. In arid areas, reclamation of produced water for beneficial uses such as irrigation or tower cooling may be an attractive alternative if the produced water can be purified to an adequate quality, specifically through the removal of dissolved components including inorganic compounds (salts, heavy metals, and radiochemicals) and organic compounds (fatty acid, aliphatic, and aromatics). Membranes technologies show advantages in both energy efficiency and high water quality. Due to the presence of dissolved organics, reverse osmosis with organic membranes is highly limited. Research efforts focus on developing new materials that are less prone to fouling and are easy to regenerate. Novel ceramic membranes are relatively new classes of material that show promising application in produced water purification due to their extreme stability in harsh environments and optional choices for regeneration. This paper details the results of investigations of produced water purification by microporous ceramic membranes, including metal oxide membranes, clay membranes, and zeolite membranes. Techniques for membrane fabrication, process design, and economic aspects are also discussed.

Silver-embedded zeolite thin film-based fiber optic sensor for in situ, real-time monitoring Hg2+ ions in aqueous media with high sensitivity and selectivity

This work demonstrates that a silver-embedded zeolite thin film based fiber optic sensor can be used for in situ, real-time monitoring Hg2+ in aqueous solution, with high sensitivity and selectivity over competing analytes. The reflection intensity from the zeolite-coated fiber was observed that changes monotonically with the variation of Hg2+ concentrations.

An integrated chemical sensor for downhole CO2 monitoring in carbon sequestration

A Severinghaus-type CO2 sensor was prepared for in-situ downhole CO2 monitoring during geological carbon sequestration. The sensor consists of: a porous support material; gas-permeable membranes coated onto the inner and outer surface of the support material; a metal-oxide electrode and a reference electrode; and an internal electrolyte composed of equal amounts of bicarbonate source and a halide salt. The sensor was tested by measuring the output potential between the metal-oxide electrode and the reference electrode. The prepared CO2 sensor demonstrated an excellent linear interrelation between the sensor response potential and the logarithm of the CO2 concentration at high pressure. A microcontroller-based data acquisition system was designed for downhole CO2 sensor data logging, which could convert the sensors analog signal to a digital signal without discharging the sensor during data collection.